Variable focal length lens systems suitable for use with a solid-state imaging device have been disclosed in the Japanese Patent Laid-Open Publication No. 6-94996 and in the Japanese Patent Laid-Open Publication No.7-261083, etc.
Every one of embodiments disclosed in the Japanese Patent Laid-Open Publication No. 6-94996, however, has a zoom ratio such as about 2, and it is not sufficient.
In each embodiment disclosed in the Japanese Patent Laid-Open Publication No. 7-261083, the zoom ratio is about 2.3, and it is still not sufficient. Further, a variation of spherical aberration in accordance with zooming is large and imaging quality is not sufficient as shown in aberration charts disclosed in the publication.